Will allowing your child a sip of wine at an early age prevent him from engaging in dangerous drinking later? Probably not, but plenty of parents think so, finds a recent study.

A survey published this week in the journal Archives of Pediatrics & Adolescent Medicine interviewed 1,050 mothers and their third-graders, and found that a substantial proportion of parents — anywhere from 15% to 40% — believe that letting their kids taste alcohol at home will protect them from engaging in risky drinking behaviors with their peers later on. As expected, the children of moms who held such beliefs were more likely to have tried alcohol by about age 9.

For the study, researchers interviewed mothers and their kids for 25 minutes each. Mothers were asked to rate how much they agreed with statements like “If parents don’t let children try alcohol at least once, children will be more tempted by alcohol as a ‘forbidden fruit,'” “Letting children younger than 12 years have sips or tastes of alcohol is a safe way to introduce them to alcohol” and “Children who sip small amounts of alcohol at home with parents will be less likely to experiment with risky drinking in middle school.”

The third-graders were asked whether they had ever tasted a sip of beer, wine or any other alcohol, and whether an adult in their home had ever allowed them to do so. Approximately a third of the child participants reported sipping alcohol.

Moms were most likely to believe the forbidden-fruit argument — 1 in 3 mothers agreed that keeping alcohol from their kids would only make them want it more and that it would increase its “forbidden fruit” appeal. About 22% of moms thought that children who learn to sip alcohol at home would be better at resisting peer pressure to drink outside the home, and 26% believed that kids who try drinking with their parents will be less likely to experiment with alcohol in middle school. The researchers note, however, that it’s a mistake to think that kids’ drinking behaviors at home, under parental supervision, have any bearing on the way they drink with their friends — recent studies refute that notion.

In fact, there’s little evidence to suggest that early exposure to alcohol curbs drinking in adolescence. Rather, the opposite may be true. The authors cite previous research showing that, for example, fifth-grade children whose parents allowed them to have alcohol were twice as likely to report recent alcohol use in seventh grade. Another study found that sipping or tasting alcohol at age 10 predicted drinking by age 14, even after controlling for other psychological or social factors that could increase the risk of problem drinking.

Belief in the protective effect of early alcohol sipping was most common in white, college-educated, employed women. The researchers speculate that this could be because drinking is more socially acceptable among this group, so parents are more tolerant of underage drinking. It could also be that women in this group are more concerned than other moms about preventing underage drinking, and thus more likely to try to curb the behavior by introducing alcohol to their kids early.

Lead study author Christine Jackson, a public health analyst at the Research Triangle Institute in North Carolina, notes that parents who hold such pro-sipping beliefs are not only more tolerant of their children tasting alcohol, but they’re also more likely to involve their kids in adult alcohol-related activities, like letting them fetch or pour drinks for adults — all of which could have unintended effects.

“It is possible that an early introduction to alcohol, even when it is limited to sips and even when it is meant to discourage child interest in alcohol, could backfire…leading to more drinking later on,” says Jackson. The authors call for further examination into the effects of parents’ pro-sipping beliefs on children’s alcohol use as they grow older.

“Public health education programs are needed so that more parents know that home drinking norms do not curtail risky drinking in peer contexts,” the authors conclude.